Work holder for broaching machines



Sept. 21, 1943 o. W. BONNAFE WORK HOLDER FOR BROACHING MACHINES Filed Sept. 1l, 1941 4 Sheets-Sheet l NHNHRN Sept. 21, 1943. o. w. BoNNAFE WORK HOLDER FOR BROACHING MACHINES 4 sneetsL-sheet 2 Filed Sept. ll. 1941 `hw une?. onwenw. omxwe Sept. 21, 1943.

O. W. BONNAFE WORK HOLDER FOR BROAGHING MACHINES 4 sheetslsheet s Filed Sept. l1, 1941 muwvok Ouv ER Womwwi Sept 2l, 194:3- 4 o. w. BONNAFE y 2,329,976

WORK HOLDER FOR BROACHING MACHINES mum-ron Onweawomm.

Patented Sept. 21, 1943 i i 2,329,97e

WoRK HOLDER Foa BaoAcniNG MACHINES Oliver W. Bonnafe, Hudson'.l Magda. assign@ to The Lapointe Machine Top Mass., a corporation of lVIainek nani/Hodson operation. sweater 11, nii, 'sind tioesi 12 claims. (C1. edgar) Thisy invention relates to machines for breaching tubular work, such as gun barrels, and relates particularly to machines in which a plurality'cf breaches operate simultaneously and progressively on a plurality of Work pieces. A

It is the general object of my invention to pro.-

vide an improved work, holder for such aV ma? chine, so constructed that several Work pieces may be supported therein and simultaneously advanced to successive breaching positions, and also providing intermediate broachfreturn positions.

A further object of my invention is to provide means to rotate each of the several work piecesv about its own axis during the broaching operation and in predetermined relation to the longitudinal movement of the breaches through the work.

I also provide improved hydraulic means'for intermittently advancing the work holder and for locking the work holder in broaching and in broach-return positions. Another feature ofthe invention relates to the provision of improved means forv cooling the broaches and for lubricating the work during -each broaching operation.

My invention further relates to arrangements and combinations of parts which will behereinafter described and more particularly pointed'out in the appended claims. 1 f' A preferred form of the invention is shown in the drawings, in which Fig. 1 is a sectional side elevation of the work holder, partly broken away and taken along the irregular. line I-I in Figs. 2 and `4; f

Fig. 2 is a transverse sectional elevation, taken along the line 2-2 in Fig. 1 and showing the head portion of the work holder, partially broken away;

Fig. 3 is a partial detail front elevation ofthe head portion, looking in the direction of the. arrow 3 in Fig. 2; l

Fig. 4 is a transverse sectional elevation, taken along the line 4 4 in Fig. 1 and showing the tail portion of the work holder;

Fig. 5 is a partial sectional front elevation .of a broach pulling device `associated with my improvedwork holder; l n i Fig. 6 is a sectional elevation of a hydraulic cylinder which operatesa locking device; and

Fig. 7 is a sectional side elevation of a hydraulic cylinder and control valve which operatesa feeding device.

My improved work holder comprises a head portion H and a tail lportion T, both mounted on rxed guide-.bars H? Fies, ,1. 2 4.).. The hoed Chine and' is. rovigo `the left in Fig portion Ii Coiomoeii Secured fixed relation to the guide-bars lil but the tail portiorlif'-is., sutiable. tiiofooo and may be. Soo-umd i loneitiidinalpo. n vaiolo no oiiign derdmined bv the'lenei .suoi die euri barrels oiA other Work nieces, t9 be breached- The. worls holder iri tiledfrwiiieo iS. do: signed toha five working posiiiiio. arid ozio loading n @dually Showed @irait oir-Cum.: f ereniialia and a o iilavid d with an 1 tra mediato brooch-rotura moitie biitoii oo two work-holding or work-loading positions:Av

The .nood portion @remedies .a niemeer l2 having a feed rige ld .Seured to the basil; .Side thereof', ,as byfsorovs iii,- one .8 is prorided withnotooos, id iFie- 2). ooirosiioiidirie inl ber and specie-e to the dumber and Sodome of the' workflioldiiie .and breach-rotore modifies, A oovernla-te 2 2 holds 'the in@ .l2-: d fiile lain rotatable assemloled relation in the f ,ine lli, Six work-holding devioosaro piovidedin the head portion and one o fV these devices id slidwh in section infile. 1.1 f

Each Workfholdirie device comprises a hollow spindle 3.0 having de' enlareediiead iooessosi and sorratodfto receive.. senior and siii), the Serratedendof az' Ork pietre W, The spiodle 30, is rotatablymo d on ball hearings 3%. the outer `races o f y are sed .in the member l? previously described.

At its rear end. each spindle .Sli is provided .with agear 33 which meshes with a pinion '35 (Fig. 2) mounted on the member 12.: All ,of .the pinions` 35 are engaged and driven by a gear 3T, mounted concentric with Ythe member l2 Yupon ball bearings 3- 8 and s pdirall-y groovd internally to coact withspiral splines on a shaft `744|. The shaft 4l 'is 'secured' to `the broaching-head of the maf I 1 ly "through the" worl; holder define the bioeiil operated dit Wiih# out lng-)pawn The broaching head andits operatingineans iorms no por@ of mifrreoeni loven o .and nier loe of die mooiieoially 'operated iv ot i.' toofprior or to LB No. 1.43 '6211. or .o f the hydraulically operai ivre ,Sher-,d1 et.' .L3 in the prior potent' .t9 Woot.; No id. f #plurality-Qi bioeohes Qrrpoodiiioli ber to the' brpaching siti I ioldory iiaveiheir deogeiedflifio 'ioid froid ood are -Sooirodto thoxliioechieg'iiegd 'os hoyo in said patents. lThe breachesA and the shaft "4l 1 through .the hollow` worl y pieces drawn laidolly through die yorkiiiaoo bili providing the desired lead or twist for the rifle grooves.

The tail portion T comprises a frame 50 in which a member is rotatably mounted, and said member is provided with a plurality of workenga-ging devices, each comprising a concally recessed work-centering device 52, slidably mounted in the hub of a spindle 53, which in turn is mounted on ball bearings 54 in the rotary member 5|. wardly to yieldingly engage the end of the Work W.

A heavy tube 68 is rmly secured by welding or otherwise to the rotary member I2 and in its left hand portion (as shown in Fig. 1) is provided with a plurality of keys 6| coacting with corresponding keyways in the rotary member 5|. Consequently the tail portion T can be mounted in different axial positions on the guideways I0 but in every position the members l2 and 5| Will be positively connected for simultaneous rotation.

At the intermediate or broach-return positions, openings 65 and 66 are provided in the members I2 and 5| respectively, and a guide tube 61 of suitable length is inserted in the recessed outer portions of each pair of these openings, to guide and protect the broaches during their return movement within the guide tubes. Sets of tubes 61 of different lengths are provided for different spacing of the head and tail portions.

A locking pawl 10 (Fig. 2) and a feed pawl 1| are provided in the head portion H to coact with the notches in the ring |8. During a broaching operation, the locking pawl 'IU occupies the f position shown in Fig. 2 and rrnly holds the work holder from angular displacement. When a broaching operation is completed, the locking pawl 'I0 is withdrawn by a hydraulically-operated piston, and the feed pawl His also drawn upward preliminary to a feeding stroke.` The feed pawl then moves downward, advancing the work holder le of a revolution and thus bringing the broach-return tubes 61 in alignment with the broaches, which are thereupon returned through the tubes 51 to their initial positions.

As soon as the notched ring I8 begins to advance, the locking pawl 'l0 is released and thereafter rides on the periphery of the ring |8 until the next notch 20 comes under the pawl 10, whereupon the pawl drops into the notch and locks the ring |8 and associated parts from further movement.

The locking pawl is preferably operated by the single acting hydraulic cylinder and piston shown in Fig. 6 and comprising a piston 15 slidable in a cylinder 'I6 having a stop 11 to limit upward movement of the piston and also to form a guide for a spring 18. The piston15 and associated pawl 'l0 are moved downward by the spring 'I8 to locking position, while oil under pressure from a suitable source is admitted through the connection 19 to lift the pawl preliminary to a feeding operation.

The feed pawl is pivotally mounted at the Springs 55 press the devices 52 out- L lower end of a plunger 80, slidable in a guide passage 8| in the frame member I6 of the head H. The plunger is connected by a piston rod 89 to a piston 82 slidable in a cylinder83 and connected to receive oil under pressure at either end from a supply pipe 84, and to discharge the same through an exhaust pipe 85. The direction of flow may be controlled by a rotary four-way valve 86 or in any other convenient manner.

When the valve is in the position shown in Fig. 7, the piston 82 is moved upward to withdraw the pawl 1|, and when the valve position is reversed, pressure in the upper end of the cylinder 83 forces the piston 82 and pawl 1| downward to advance the rotary member |2 one space. Special provision is made for circulating a cooling and lubricating liquid through the broaches` and work pieces during the broaching operation and this construction will now be described.

In the head portion H, the spindles 39 (Fig. 1) in the work supporting devices are made hollow and the xed frame member I 6 is provided with openings 9D which are aligned with the hollow spindles 39 when the spindles are in working position. Suitable annular plates 9| and 9|a and interposed packing provide a tight joint between the spindles 30 and openings 99.

The plate 9| rotates with the Work holder and has an opening for each work spindle and for each return tube. The plate 9|a is xed to the stationary head frame member I6 and has an opening for each broaching position but no opening for loading position. This makes five openings for a six-spindle machine as shown herein.

In the tail portion T, an extension 92 (Fig. 1) is secured to the rotary member 5|, as by screws 93, and this extension 92 is provided with openings 94 aligned with the work-holding devices 52 and with additional openings 95 aligned with the broach-return openings or passages 66.

Slidable bushings 91 (Fig. 1) are mounted in a fixed plate T and are adapted to be engaged by spring-pressed caps 98 (Fig. 5) mounted on the ends of breach-gripping devices 80 forming part of a puller head P. The devices |09 grip the tail Shanks of the broaches as they are returned through the tubes 61. The puller head P then withdraws the broaches entirely from the Work holder and later returns the broaches through the work for re-attachment to the breaching head. This return movement takes place after .the work holder has advanced the work pieces to their next broaching position.

When the` puller head P thus returns the broaches, the caps 98 engage the bushings 91 and force them inward against the member 92, thus closing the outer ends of the openings 94, except as they are open into the `interior of the broachgripping devices |90, which are themselves sealed to prevent leakage. The parts are retained in this position during the breaching operation.

Oil is supplied through a pipe |93, an annular channel |94 and ports |95 and |96 in the tail portion T to each work-centering device in said tail portion.. Suitable valve means is to be provided for shutting off the supply of lubricant while the puller head P is removed from the sealing position shown in Fig. 5.

When the work is removed from any one of the devices 52, said device moves to the right (as seen in Fig. l) and the oil supply for said device is thus cut off. Consequently no oil will be supplied to any work-centering device which is in loading position until the loading has been comasesora nl eteu.'` e, frite-plate .Slt osstated. has poi oiiopenmilitie vdetail 'structure ot. the ,roach-gripping. devices. M-.emersa be Substantially as shown-in Fiasont these devices.; forro. .Hapert ofthe present investi except as the oeps 38 serveto iforoe the buslrldssgtirrwarti anoto. Athiisolose the opep-. ings 94 in the member 92 duringthejbroaohing, operation. j

It will thus.4 be seen that 1 have; provided a Work.- holderreadly adapted to receive Work pieces of diiiereirt lengths. to hold afplurality fofwork` pieces. Ain breaching position, and to permit. reloading iny one.V position While breaching operations are.v being performed in the remaining posi-A I havealso provided means for rotating the wort; .pieces in predetermined relation vto the longitudinal. movement.. oi the loroeohes,` through theoperation of the spirallysplned shaft ill, .the aearnlf eetuated.- thereby, and theeeer penile@-A tipns toaeaoh separate work-eneasrrsidevioe irl theeeeiyportiori H:

.-I'nalso providefor forced circulation of lubrithe breaches and the work vduring each, broaching operation, it beingunderstoodthat each -broachhas an axial oil passage and branch openings therefrom to. distribute oil along. the length. ot. tbebroaoh-z Thisv brosch. construction-is, commercial and no ,illustration thereof is believed necessary. l

In the operation of the machine, the breaches are returned through the tubes 6l by the broaching head after a broaching operation has been completed and after the Work holder has been advanced to broach-return position. The broaches are then gripped by the puller head P and are fully withdrawn from the work holder. The work holder is then advanced to the next broaching position and the puller head P returns the broaches through the work until the leading shanks of the broaches are gripped by the broaching head. The broaches are then drawn through the work pieces to perform their respective broaching operations, thus completing the working cycle.

I have thus provided an improved work holder Which vis particularly well adapted to the purposes for which it is designed and to the performance of the breaching operations above set forth.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. In a broaching machine, a Work holder comprising a head portion, a tail portion, means to hold said portions in substantially spaced relation and for simultaneous rotation, said head and tail portions each having a plurality of work-engaging devices rotatably mounted therein and having intermediate broach-return positions, and means to intermittently advance said work holder alternately to breaching and to broach-return positions.

2. In a breaching machine, a Work holder comprising a head portion, a tail portion, means to hold said portions in substantially spaced relation and for simultaneous rotation, said head and tail portions each having a plurality of Workengaging devices rotatably mounted therein and having intermediate broach-return positions, and coacting hydraulic feeding and locking mechanism by which said work holder is alternately advanced to broachng and to broach-return positiensapd autpinatioally- 'toolset said poste tIlS i .a breathing rpaohipe',Y holder oom-i prisioe e. head portion..v a tail portion, means. hold said; portions substantially speeeoi reis.- tion. 'epd for, .simultan rotation.. said heartland tail portions each having o. plurality oi vorig: engaging devices rotatably mounted; therein and d` te `broaririr.return, positions,

...lio oylipoler and pist-op. to attuate. said ieedins and a sioeleeaotins hydraulic ovlintter and; piston with spring return to actu. e saicilooleioemesps. 7 4.- lizaleloe'chiee awo-rk holder-,corne prisipaaheefri. portion, a tait portion, meansfto. tolti` seitiportiorrs in substantially speoeot relation apeoirsrototiop. saiohoao and tan portions. oooh hai/ipe; aplurali-ty of; work-.ensag-.- ipa devieesrotatatly mounted. therein, and have. intermediate broophgretprn posit; 1 and presen-s .timer tubes. ooooeotinesaio 'teil- DDItiQIl. al?. seid intermediate positions...

e breathing nraohine, o vorkl holder comeV e Briefing. e head portion, a tail portion, meansto poldseitt portions irl substantie y. spaced relai. tion epd for simultaneous rotation, said vhead.:v and tail portions eachhaving a plurality ofworkengaging. devises. rotatably. v1 .1i.1.ri.ft;ed,r therein andL invite intermediate, presen-.rotem positions, and: means to simultaneously rotate all of the Workengaging devices in the head portion about their separate :axes and in predetermined relation to the longitudinal travel of the broaches relative thereto.

6. In a broaching machine, a. work holder comprising a head portion, a tail portion, means to ho-ld said portions in substantially spaced relialtion |and for simultaneous rotation, said head and tail portions each having a plurality of Workengaging devices rotatably mounted therein and having intermedi-ate broach-return positions, a spirally-splined device movable lengthwise with the broaches, and gear connections from said splined device to the work-engaging devices in said head portion, said connections being effective to simultaneously rotate said work-engaging devices -about their own axes` in predetermined relation to the longitudinal Working travel of the broaches relative thereto.

7. In a broachingmachine, a work holder comprising a head portion, la tail portion, means'to hold said portions in substantially spaced relation and for simultaneous` rotation, said head and tail portions each having a plurality of workengaging devices rotatably mounted therein and having intermediate broach-return positions, a spirally-splined device movable lengthwise With the broaches, a gear in said head portion rotated by longitudinal movement of said splined device, a separate gear for each work-engaging device in the head portion, and idle pinions connecting said latter gears to said rst gear for simultaneous actuation thereby.v

8. In a broaching machine, a Work holder comprising a head portion, la tail portion, means to hold said portions in substantially spaced relation and for simultaneous rotation, said head and tail pont-ions each having a plurality of workengaging devices rotatably mounted therein and' having intermediate broach-return positions, and means to. deliver la cooling and lubricating liquid to each broach and its associated Work piece but only during a breaching operation thereon.

9. In a broaching machine,` a work holder comprising a head portion, a tail portion, means to hold said portions in substantially spaced relation and for simultaneous rotation, said head and tail portions each having a plurality of workengaging devices rotatably mounted therein and having intermediate broach-return positions, means to deliver a cooling and lubricating liquid to each broach and its associated Work piece `but only during a breaching operation thereon, and means to seal said Work-engaging devices to prevent escape of liquid therefrom.

10. In a broaching machine having loading and Working positions, a Work holder comprising a head portion, a tail portion, means to hold said pontions in substantially spaced relation and for simultaneous rotation, said head and tail portions each having a plurality of Work-engaging devices rotatably mounted therein and having intermediate broach-return positions, means to deliver a cooling and lubricating liquid to each broach and its associated work piece but only during a broaching operation thereon, means to seal said work-engaging devices to prevent escape of liquid therefrom, and a xed Valve plate preventing delivery of liquid to said Work-engaging devices except when said devices are in working position and are out of loading position.

11. In a broaching machine, a Work holder comprising a head portion, a heavy elongated axial tube on which said head portion is secured,

a tail portion slidable on said tube but held fromv angular movement relative thereto, means to secure said tail portion in adjusted longitudinal position on said tube, and means to intermittently and simultaneously feed said heavy tube and said head and tail portions angularly to advance a plurality of work pieces to successive operating positions.

12. In a broaching machine, a Work holder comprising a head portion, a heavy elongated axial tube on which said head portion is secured, a tail portion slidable on said tube but held from angular movement relative thereto, means to secure said tail portion in adjusted longitudinal position on said tube, means to intermittently and simultaneously feed said heavy tube and said head and tail portions angularly to advance a plurality of Work pieces to successive operating positions, a spirally-splined shaft mounted within said heavy tube and slidable but non-rotatable therein, a central gear in said head portion splined to said shaft and through which said shaft is slidable, and a gear connection from said central gear to each of the work-engaging devices in said head portion, whereby said devices and the associated work pieces will be simultaneously rotated about their own axes in predetermined relation to any change in the relative axial positio-ns of said splined shaft and work holder.

OLIVER W. BONNAFE. 

